This project seeks to determine the pathophysiological role of an hypothesized shock-induced pancreatic cardiodepressant substance. Goals of this project include: the biochemical isolation and characterization of the cardiodepressant substances in the incubated pancreatic homogenate and shocked plasma, the quantification of cardiodepressant effect (upon the isolated papillary muscle and the whole heart in vivo) and quantification of the ability of selective removal of the cardiodepressant substance from the circulation of a shocked animal to forestall the termial cardiovascular collapse of irreversible shock. The accomplishment of the last goal will provide for a critical testing of the hypothesis that circulating cardiodepressant "shock" substances are the precipitating agents in the development of irreversible cardiovascular collapse in the terminal stages of shock.